The present invention concerns an assembly for a hydraulic dashpot. The dashpot is accommodated in a housing that is partitioned into two compartments by a shock-absorbing piston mounted on one end of a piston rod and accordingly traveling back and forth inside the housing. Dashpots of this genus can be solid walled or hollow-walled. The shock-absorbing piston is transversed by fluid-conveying channels provided with stacks of cupsprings that open and close to control the flow in both the vacuum phase and the pressure phase.
Low-amplitude oscillations sometimes reach the piston rod and break the cupsprings loose, leading to irregular shock absorption. European Patent 1 152 166 A1 proposes counteracting this tendency using another, vibration-compensating, piston hydraulically paralleling the shock-absorbing piston but accommodated in a subsidiary housing. The vibration-compensating piston in one embodiment is mounted on the face of the shock-absorbing piston more remote from the piston rod. There is a drawback here in that rod's radial moment of support is too short. In one alternative embodiment, the vibration-compensating piston is mounted in an adaptor between the end of the piston rod and the shock-absorbing piston. Here again there are drawbacks—the design is complicated and the shock-absorbing piston is of course not as rigidly fastened to the piston rod.